bool TryShowFocusBox()
{
Debug.Assert(FocusBox != null, "make sure sandbox is setup before trying to show it.");
if (FocusBox == null)
return false;
InstallFocusBox();
FocusBox.Visible = true;
// Refresh seems to prevent the sandbox from blanking out (LT-9922)
FocusBox.Refresh();
return true;
}